package com.mygodp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.mygodp.dto.Result;
import com.mygodp.entity.VoucherOrder;
import com.mygodp.mapper.VoucherOrderMapper;
import com.mygodp.service.ISeckillVoucherService;
import com.mygodp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.mygodp.utils.RedisWorker;
import com.mygodp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    RedisWorker redisWorker;

    @Resource
    StringRedisTemplate stringRedisTemplate;

    @Resource
    RedissonClient redissonClient;
    /*@Override
    public Result secKillVoucher(Long voucherId) {
        //1.查询优惠券信息
        SeckillVoucher seckillVoucher = seckillVoucherService.getById(voucherId);
        //2.判断秒杀是否开始
        LocalDateTime beginTime = seckillVoucher.getBeginTime();
        if(LocalDateTime.now().isBefore(beginTime)){
            return Result.fail("秒杀未开始！");
        }
        //2.1 判断是否结束
        LocalDateTime endTime = seckillVoucher.getEndTime();
        if(LocalDateTime.now().isAfter(endTime)){
            return Result.fail("秒杀已结束！");
        }
        //3.判断库存是否充足
        Integer stock = seckillVoucher.getStock();
        if(seckillVoucher.getStock()<1){
            return Result.fail("秒杀券库存不足！");
        }

        //一人一单
        Long userId = UserHolder.getUser().getId();
//        synchronized (userId.toString().intern()){
//        SimpleRedisLock simpleRedisLock = new SimpleRedisLock("order" + userId, stringRedisTemplate);

        //创建锁参数
        RLock lock = redissonClient.getLock("lock:order" + userId);
        //获取锁
        boolean isLock = lock.tryLock();
        //判断锁是否获取成功
        if(!isLock){
            return Result.fail("不允许重复下单！");
        }
        try {
            //获取代理对象(事务)
            IVoucherOrderService proxy =(IVoucherOrderService) AopContext.currentProxy();
            //6.返回订单id
            return proxy.createVoucherOrder(voucherId);
        }finally {
            //释放锁
            lock.unlock();
        }
    }*/
    //配置lua脚本
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }


    //线程
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();


    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }


    private class VoucherOrderHandler implements Runnable{
        String queueName = "stream.orders";

        @Override
        public void run() {
            while (true){

                try {
                    //1.获取消息队列中的订单信息 XREADGROUP GROUP g1 count 1 block 2000 streams streams.order >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    //2.判断消息获取是否成功
                    if(list==null||list.isEmpty()){
                        //如果获取失败，说明没有消息，继续下一次循环
                        continue;
                    }
                    //3.解析消息中的订单信息
                    MapRecord<String ,Object,Object> recode = list.get(0);
                    Map<Object,Object> values = recode.getValue();
                    VoucherOrder  voucherOrder =  BeanUtil.fillBeanWithMap(values,new VoucherOrder(),true);
                    // 4.如果获取成功，可以下单
                    handleVoucherOrder(voucherOrder);
                    // 5.ack确认 sack stream.orders g1 id
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",recode.getId());
                    //2.创建订单
                    handleVoucherOrder(voucherOrder);
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    handlePendingList();
                }

            }
        }

        private void handlePendingList() {
            while (true){

                try {
                    //1.获取pending-list队列中的订单信息 XREADGROUP GROUP g1 count 1 streams streams.order 0
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    //2.判断消息获取是否成功
                    if(list==null||list.isEmpty()){
                        //如果获取失败，说明pending-list没有异常消息，结束循环
                        break;
                    }
                    //3.解析消息中的订单信息
                    MapRecord<String ,Object,Object> recode = list.get(0);
                    Map<Object,Object> values = recode.getValue();
                    VoucherOrder  voucherOrder =  BeanUtil.fillBeanWithMap(values,new VoucherOrder(),true);
                    // 4.如果获取成功，可以下单
                    handleVoucherOrder(voucherOrder);
                    // 5.ack确认 sack stream.orders g1 id
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",recode.getId());
                    //2.创建订单
                    handleVoucherOrder(voucherOrder);
                } catch (Exception e) {
                    log.error("处理pending-list订单异常",e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        ex.printStackTrace();
                    }
                }

            }
        }
        /*//阻塞队列
        private BlockingQueue<VoucherOrder> orderTasks =  new ArrayBlockingQueue<>(1024*1024);
        @Override
        public void run() {
            while (true){

                try {
                    //1.获取队列中的订单信息
                    VoucherOrder voucherOrder = orderTasks.take();
                    //2.创建订单
                    handleVoucherOrder(voucherOrder);
                } catch (Exception e) {
                    log.error("处理订单日常",e);
                }

            }
        }*/
    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        //创建锁参数
        RLock lock = redissonClient.getLock("lock:order" + userId);
        //获取锁
        boolean isLock = lock.tryLock();
        //判断锁是否获取成功
        if(!isLock){
            log.error("不允许重复下单！");
            return;
        }
        try {
            //数据库写入订单
           proxy.createVoucherOrder(voucherOrder);
        }finally {
            //释放锁
            lock.unlock();
        }
    }

    //获取代理对象(事务)
    IVoucherOrderService proxy;

    @Override
    public Result secKillVoucher(Long voucherId) {
        //1.执行lua脚本
        Long userId = UserHolder.getUser().getId();
        //订单id 全局id生成器
        long orderId = redisWorker.nextId("order");
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString(),String.valueOf(orderId)
        );

        //2.判断结果是否为0
        int r = result.intValue();
        if(r!=0){
            //3.否返回异常信息
            return Result.fail(r==1?"库存不足":"不能重复下单");
        }
        //获取代理对象
        proxy= (IVoucherOrderService) AopContext.currentProxy();
        //5.返回订单
        return Result.ok(orderId);
    }

    /*@Override
    public Result secKillVoucher(Long voucherId) {
        //1.执行lua脚本
        Long userId = UserHolder.getUser().getId();
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString()
        );

        //2.判断结果是否为0
        int r = result.intValue();
        if(r!=0){
            //3.否返回异常信息
            return Result.fail(r==1?"库存不足":"不能重复下单");
        }
        //5.创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        //用户id
        voucherOrder.setUserId(UserHolder.getUser().getId());
        //秒杀券id
        voucherOrder.setVoucherId(voucherId);
        //订单id 全局id生成器
        long orderId = redisWorker.nextId("order");
        voucherOrder.setId(orderId);
        //4.将优惠卷id,用户id和订单id存入阻塞队列
        orderTasks.add(voucherOrder);
        //获取代理对象
        proxy= (IVoucherOrderService) AopContext.currentProxy();
        //5.返回订单
        return Result.ok(orderId);
    }*/

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder){
        //一人一单
        Long userId = voucherOrder.getUserId();
        //查询订单
        int count = query().eq("user_id",userId).eq("voucher_id",voucherOrder.getVoucherId()).count();
        //判断是否存在
        if(count>0){
            //用户已经购买过
            log.error("用户已经购买过!");
            return;
        }

        //4.扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock -1")
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock",0)
                .update();
        if(!success){
            //扣减失败
            log.error("秒杀券库存不足！");
            return;
        }
        /*//5.创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        //用户id
        voucherOrder.setUserId(UserHolder.getUser().getId());
        //秒杀券id
        voucherOrder.setVoucherId(voucherId);
        //订单id 全局id生成器
        long orderId = redisWorker.nextId("order");
        voucherOrder.setId(orderId);*/

        save(voucherOrder);

    }
}
